The present invention relates to humidifying devices.
Humidifying devices of the type for humififying and heating a breathable gas such as oxygen supplemented air to be inhaled by a patient undergoing inhalation therapy are known. Such devices may comprise an annular metallic cylinder and a sleeve for heating an outer surface of the cylinder. Such devices also have an annular absorptive column located against an inner surface of the cylinder. Such devices may also have a reservoir containing sterile water, and a conduit connecting a lower portion of the reservoir with a lower portion of the cylinder for flow of water from the reservoir into a lower portion of the cylinder.
Although such devices have operated satisfactorily, difficulty has been found with the absorptive column particularly when the devices have been operated over extended periods of time. It has been found that after operation of a few hours the prior column becomes soft and loses its shape resulting in poor heat conduction from the sleeve. Also, it has been found that pockets of air form between the column and cylinder, which also causes poor heat transfer.